Ever since I got my dragon I had been buying from Dubiaroaches.com. I tried dubi deli once but I didn't like the burlap bag they come in and I had a lot of deaths.
For the incoming winter weather I just placed an order for 3000 supers from rainbowmealworms while I let my roach colony recuperate...
Ceramic heat emitter is the way to go.
Just play around checking the humidity and temperature in between moving the bulb higher or closer from the bin. Too close and you get a higher temp but the humidity goes down real quick.
You have to find the sweet spot.
After a couple days I finally...
I had 300 in a cricket keeper with a piece of egg carton as long as the cage.
A tray of food and a tray of water crystals.
My dragon got so fat off of them it made me so proud.
I read and bought and did everything the same as you and ended up with the same results.
So I have the heating pad on medium on the bottom and a ceramic heat emitter over the top.
Temp maxes at 86°